https://www.selleckchem.com/products/idasanutlin-rg-7388.html 2352 T > C SNP had a significantly higher meat ratio ( P   =  0.002) and lower back-fat thickness ( P   =  0.004) than those of the other genotype. Moreover, although the least square means of steers with CC-CC, CT-CC, and TT-CC genotypes were significantly decreased for back-fat thickness, they were significantly increased for the meat ratio. Therefore, our results suggested that g.111 T > C SNP and g.2352 T > C SNP could be a causal mutation related to an adipose metabolism in Korean cattle steer.The use of specialized meat breeds in cattle breeding programs is considered very promising for improving herds' productivity. However, in animal genotype, along with genes that positively affect the productivity signs, there are genes whose mutations, known as genetic defects, negatively affect the health of animals. The aim of the study was the screening of the Russian populations of Aberdeen Angus, Hereford and Belgian Blue cattle on gene mutations associated with the genetic defects of arthrogryposis multiplex (AM), osteopetrosis (OS), developmental duplication (DD), double muscling (M1), hypotrichosis (HY) and maple syrup urine disease (MSUD) as well as the F94L polymorphism of myostatin gene (MSTN) linked with the gene responsible for less fat content in the carcass by means of DNA analysis. In the article, test systems based on the polymerase chain reaction method are presented. The analysis of the Aberdeen Angus ( n = 4480 ) population has revealed 0.19  ±  0.09 % animal M1 carriers, 0.53  ±  0.03 % OS carriers, 1.92  ±  0.09 % AM carriers and 9.00  ±  0.20 % DD carriers. The genotyping of Hereford cattle of Russian populations ( n = 525 ) has not revealed any individual carriers of MSUD or HY genetic defects. All of the Belgian Blue population ( n = 92 ) animals were heterozygous M1 carriers. The study of the F94LMSTN polymorphism has demonstrated extremely high frequencies of the desirable A allele (0